California Institute for Energy and Environment (CIEE)

Long-term variations in climate (temperature and precipitation) in portions of California are not sufficiently well sampled in some remote areas lacking meteorological or hydrological stations. A combined strategy of small clusters of climate stations arranged from the coast to the mountains was adopted to guide the deployment of a network of new long-term monitoring sites. This strategy for the stations installed as part of this project was suggested through consultation with research and operational entities throughout the state but priority was given to stations located in the coastal environment and high elevations above the average winter snow line. A set of 15 sites had instruments installed to become a part of this study; they provide on-going measurements with 10-minute resolution, at elevations ranging from sea level to over 14,000 feet. Almost the entire range of elevation in California is now sampled for climate monitoring as a result of this project. Most stations are located where future site disruption is judged to be unlikely. A few sites were established to monitor particular climate elements such as wind, temperature or humidity. Coastal sites have shown very large differences in short vertical and horizontal distances, confirming the rationale for close spacing in certain settings. Measure data are posted immediately to the web. Methods to graph, summarize, and download the data have been working very well. Experimental techniques are showing that higher elevations appear to have begun warming significantly over the last 1-2 decades in comparison with lower elevation areas. The project motivated the development of the California Climate Tracker, a method for showing the climate history of the state and 11 subregions for the past 115 years. This tool is intended for a wide audience and can be accessed through the California Climate Data Archive and the Western Regional Climate Center.